The objectives of this research are to identify electrical, neural and hormonal controls of gastrointestinal motility in health and disease. Using in vivo techniques in man and dogs, electric activity will be studied using silver electrodes, motility using balloons, open-tipped catheters, strain gauges, and cinefluorography, and emptying using radioactive meals, plastic spheres and solutions. Control patterns will be stressed by electric pacing, by administering pure hormones and chemicals, and by operations. BIBLIOGRAPHIC REFERENCES: Gladen, H.E., and Kelly, K.A.: Independence of canine gastric and duodenal pacesetter potentials shown by electric pacing. Proc. Mayo Clinic, 52:51-53, 1977. Hinder, R.A. and Kelly, K.A.: Human gastric pacesetter potential: site of origin, spread and response to gastric transection and proximal gastric vagotomy. Am. J. Surg., 133:29-33, 1977.